More from the eagle-eyed Colin Gleadell who gets down to brass tacks on Sotheby’s run of very strong sales Russian Modernist works at the beginning of their sale last week. The value here came not from the fame of the collector so much as the quality of the documentation. Russian Modernist works are very popular on the dark side of the art world:

Fortunately, Sotheby’s had paperwork that traced ownership back to the artists, some through Cologne’s Galerie Gmurzynska, which was able to access work inside Russia in the Seventies. Others, like a small drawing of a peasant’s head by Malevich and a still life by Alexandra Exter, are included in studies by leading art historian Andrei Nakov. In addition, Sotheby’s supplied photographs relating to the works, and put each one through a chemical analysis to see if the pigments matched the dating.

Such was the hunger for fully authenticated avant-garde works of this period, few of which ever come to auction, that the collection, estimated at £3.4 million, sold for £11.6 million, seven of the works setting auction records. The Malevich tripled estimates to sell for £2.1 million. A 1912 painting by Aristarkh Lentulov, bought in 1974 for £180, also sold for £2.1 million.

A futuristic Figure with a Guitar by Varvara Stepanova, the wife of Alexander Rodchenko, was the first oil painting by her at auction since 1988, and sold for six times its estimate, at £1.7 million.